Deformation twinning in single-crystal Mg under high strain rate tensile loading: A time-resolved X-ray diffraction study

We investigate deformation twinning in single-crystal Mg with in situ, time-resolved (μs-scale), synchrotron X-ray diffraction under high strain rate split Hopkinson tension bar loading. Extension twinning occurs upon dynamic tension along 〈0001〉, but is absent upon tension along 〈112̄0〉. Such deformation anisotropy is a result of the unipolarity of deformation twinning which depends on directionality and resolved shear stress. The twinning mechanism is common for pure Mg in a wide range of strain rates and different loading conditions (one-dimensional stress and one-dimensional strain).